The following invention relates to a resurfacing machine for resurfacing babbit guide plugs disposed on either side of a saw guide.
Circular saws are sometimes included in saw arrays for performing such tasks as edging and cutting logs into boards of various thicknesses. Such circular saw arrays are designed to cut boards with a very narrow kerf so as to maximize the yield from a log or cant which may be fed into the array. In order to keep the kerf very small, saw guides are necessary to insure that the circular saws in the saw array do not wobble and maintain their alignment so that all cuts are parallel. These types of saw guides include what are known in the industry as babbit guide plugs which are disc-shaped replacable pads which are mounted on either side of the saw guide. The babbit guide plugs are wear parts, that is, portions of the circular saw blades make contact with the plugs as the plugs maintain the planar orientation of the circular saws. It is necessary to remachine or resurface the guide plugs an average of once every 16 hours that the saw array is in use.
The accuracy of the cut of the circular saw array can be maintained only if the babbit guide plugs of the saw guides have parallel surfaces. Unevenly worn guide plug surfaces or surfaces on either side of the saw guide which are out of parallelism may cause the circular saw array to cut with a wider kerf or cut uneven or nonparallel boards. It is therefore necessary, in such a resurfacing process, to maintain parallelism on both sides of the saw guide, that is, the babbit guide plugs when resurfaced should have surfaces that are parallel to each other.
In the past, resurfacing machines have been available which performed the task of resurfacing the guide plugs. An example of such a machine is a resurfacer available from Industrial Machine Co. of Battleground, Washington. This resurfacer includes a single turntable which has a cutting stylus which rotates at a high speed. The saw guides are placed on a movable magnetic base and manually moved into engagement with the turntable. As the babbit guide plug moves across the surface of the turntable the cutting stylus abrades the plug by cutting a continuous series of arcs thereby creating a smooth surface. The saw guide is then turned over onto its other side and the opposite side plug is moved across the turntable.
One problem with the aforementioned device is that since both sides of the guide plug are machined separately, there is no assurance that the two sides will be parallel. Small differences in the manner of manually moving the plugs into engagement with the turntable or of placing the saw guide on the magnetic base can lead to a non-uniform resurfacing the plugs. With manual operation there is always the possibility that the two sides of the saw guide could have at least portions of their surfaces cut differently thereby causing the two surfaces to be nonuniform or nonparallel. Resurfacing one side at a time also takes twice as long.
Yet an additional problem is that the motorized turntable of the aforementioned device is directly connected to its driving motor. Thus, vibration from the motor is transmitted to the spinning turntable which further degrades the precision of the abrading process.
What is needed, therefore, is a saw guide resurfacing apparatus capable of precise remachining of the surfaces of the guide plugs so that those surfaces are uniformly smooth and parallel to each other.